1. Field
The present disclosure relates generally to the fields of aviation and aerospace engineering. More particularly, in one exemplary aspect, the present disclosure is directed to methods and apparatus for vertical short takeoff and landing.
2. Description of Related Technology
A wide range of aviation related applications require flexibility in aircraft movement. Common requirements are vertical or short takeoff, hovering capabilities, and frequent changes in flight vector, etc. Additionally, unmanned aircraft are in high demand for defense or other applications (such as drug surveillance or interdiction) in which deploying personnel is either too dangerous or impractical given the task requirements.
It is impossible to design aircraft that meet the needs of every aviation application. Therefore, having a wide variety aircraft designs utilizing a wide variety of flight systems (e.g. propulsion, takeoff, landing etc) is necessary to match the requirements of a multitude of tasks. However, given monetary constraints, there is a practical limit to the number of aircraft that can be manufactured and dedicated to any specific purpose or group. Therefore, it is important that selected designs offer the broadest task flexibility possible, while not overlapping unduly with aircraft already in widespread use.
Existing solutions for vertical short takeoff and landing (VSTOL) generally either comprise: (i) those driven by a main rotor stabilized via a tail rotor (e.g., helicopter), (ii) more traditional airplane driven by engines or turbines the can be placed in multiple orientations (e.g., V-22 Osprey or Harrier jets), or (iii) small craft dependent on one or more turbines (Multipurpose Security and Surveillance Mission Platform or SoloTrek Exo-Skeletor Flying Vehicle). While the more traditional plane designs offer high-top speeds, and increase mission range/duration via gliding capabilities, these systems are limited in the speed at which they can accommodate a significant change in flight vector. Thus, these vehicles would be inappropriate for e.g., low-altitude applications in an urban environment. Conversely, helicopters and smaller turbine based craft lack the capability to remain aloft without expending significant power or fuel resources to keep their turbines running. Moreover, all of these vehicles have a preferred orientation such that if they become inverted, the craft will have to be righted before lift capability can be restored.
Unfortunately, modern applications often require both flight through confined areas and long on-station dwell or long-range deployment of the aircraft. Moreover, vehicles used in such applications may often experience violent disruptions or turbulence in their immediate airspace. Thus, losing lift capability as a result of environmental conditions or an unexpected inversion is a significant operational limitation.
Accordingly, improved solutions are required for VSTOL. Such improved solutions should ideally be flexible enough for urban or other confined area navigation, be able to generate lift in multiple orientations, and have suitable on-station dwell and range operational capacity.